Barren-Ground Caribou: The caribou migrate from from winter ranges in boreal forests to calving ranges on the barren grounds. Caribou move southward in the summer to escape flies, mosquitoes, and wolves. In september they are back in the boreal forests, and they mate in October.

Fur Seals: Seals breed on the Pribilof Islands off the coast of Alaska. Females winter in Southern California, then journey as much as 2800 km across open ocean and arrivin in the spring at the Pribilofs where they congregate in enormous numbers. A few days after arrival, calves are born, then the bulls collect groups of cows and guard them. After the calves have been nursed for about 3 months, cows and juveniles leave for their long migration southward. Bulls remain in the gulf of Alaska during winter.